Conduit stub-up assembly

ABSTRACT

A conduit stub-up assembly as disclosed herein comprises a conduit connector comprising a connector body including first and second openings for selectively receiving conduit end portions. The second opening has a threading element and is of a select diameter corresponding to a size of conduit end portions. A conduit stub-up form comprises an elongate tubular wall having a shoulder connected to a narrowed cylindrical neck closed at a distal end. The elongate tubular wall is of a diameter greater than the select diameter and the neck has a size to be removably received in the second opening and being engagable by the threading element.

FIELD OF THE INVENTION

The present disclosure generally relates to electrical conduitconnections, and more particularly pertains to assemblies and methodssuitable for in-slab conduit connections.

BACKGROUND

In slab-on-grade, suspended slab concrete structures and slab-on-metaldeck construction it is often a standard practice to install electricalconduit raceways within the body of the concrete slab. In order to beable to continue the conduit raceway vertically after concreteplacement, the conduit is left extending above the top of slabapproximately, for example, six to twelve inches above the top of theslab, to allow the in-slab conduit to be coupled to the future extensionof the raceway. This section of conduit extending above the final slabelevation is commonly referred to as a “conduit stub-up”. The conduitstub-up may enable the use of conventional conduit couplings, such as aset-screw fitting, which may sleeve over the two pieces of conduit beingjoined together.

Because the conventional conduit stub-up extend above the top surface ofthe concrete slabs, some form of protection may often be provided aroundconduit stub-ups to reduce the likelihood of damage to the conduit aswell as injury to unaware and/or unsuspecting workers or lay people. Forexample, damage to the conduit may make it difficult and expensive,perhaps prohibitively so, to couple the in-slab conduit to an additionalsection of conduit above the slab. In addition to possible damage to theconduit itself, the conduit stub-ups extending above the concrete slabmay pose a tripping, impalement, or other safety hazard. For thesereasons, various approaches may be utilized to identify and/or protectthe protruding conduit stub-up (and/or to protect individual from safetyhazards associated with the conduit stub-up). Examples of attemptedsafety measures may include spraying the conduit stub-ups and supportingstructure with safety orange paint, attaching flags to the conduitstub-ups, covering the conduit stub-ups with miscellaneous objects suchas CMU blocks and painting the objects a safety orange, and, insituations where groupings of conduit stub-ups occur in-line with eachother, wood blocking may be strapped to stub-ups in order to protectthem from damage and sprayed with orange safety paint to make them morevisible.

This application is directed to improvements in providing in-slabconduit connections.

SUMMARY

There is disclosed herein a conduit stub-up assembly comprising aconduit connector comprising a connector body including first and secondopenings for selectively receiving conduit end portions. The secondopening has a threading element and is of a select diametercorresponding to a size of conduit end portions. A conduit stub-up formcomprises an elongate tubular wall having a shoulder connected to anarrowed cylindrical neck closed at a distal end. The elongate tubularwall is of a diameter greater than the select diameter and the neck hasa size to be removably received in the second opening and beingengagable by the threading element.

It is a feature that the narrowed neck may comprise a threaded neck.

It is another feature that the conduit stub-up form may be of plasticconstruction wherein the neck can be inserted linearly into the secondopening and removed by rotating the conduit stub-up form.

It is a further feature that the tubular wall includes an enlargedgripping head opposite the neck.

It is another feature that the conduit stub-up form may be of one pieceplastic construction having a generally smooth outer surface.

It is still another feature that the conduit stub-up form may be hollow.

It is an additional feature that the neck may be threaded and thetubular wall portion may have a diameter in the range of ¾″ to ⅞″greater than a diameter of the neck.

It is yet another feature that the neck has a smooth outer surface andthe tubular wall portion may have a diameter in the range of ½″ to ⅞″greater than a diameter of the neck.

It is still a further feature that the tubular wall may have a draft ofabout 1°.

It is yet an additional feature that the conduit stub-up form may have agenerally uniform wall thickness of about 0.075 inches.

There is disclosed in accordance with another aspect a method ofproviding an in-slab conduit stub-up connection comprising: coupling afirst end of a conduit connector to an in-slab conduit; coupling atubular form with a second end of the conduit connector, the second endhaving a threading element, the tubular form extending above an intendedslab grade; pouring a concrete slab surrounding at least a portion ofthe in-slab conduit in the conduit connector, the tubular form extendingabove the slab; and threadably removing the tubular form from theconduit connector.

Other features and advantages will be apparent from a review of theentire specification, including the appended claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of use of a conduit stub-up form inaccordance with a first embodiment of the invention;

FIG. 2 is a sectional view illustrating removal of a portion of thestub-up form, in use;

FIG. 3A is a sectional view taken along the line 3A-3A of FIG. 1;

FIG. 3B is a sectional view taken along the line 3B-3B of FIG. 1;

FIG. 4 is a perspective view, similar to FIG. 1, illustrating adifferent conduit configuration;

FIG. 5 is a partial perspective view, similar to FIG. 1, illustratingremoval of the conduit stub-up form;

FIG. 6 is a partial perspective view, similar to FIG. 5, illustratinginstallation of a conduit subsequent to removal of the conduit stub-upform;

FIG. 7 is a perspective view illustrating a conduit stub-up formassembly in accordance with another embodiment of the invention using apush on conduit connector;

FIG. 8 is a sectional view taken along the line 8-8 of FIG. 7;

FIG. 9 is a sectional view similar to FIG. 8 showing the conduit stub-upform during removal.

FIG. 10 is a sectional view similar to FIG. 9 illustrating insertion ofa plug after removal of the stub-up form;

FIG. 11 is a sectional view, similar to FIG. 9, illustrating insertionof a conduit;

FIG. 12A is a sectional view of the conduit stub-up form used with theembodiment of FIG. 7;

FIG. 12B is a sectional view, similar to that in FIG. 12A, of a conduitstub-up form including a central interior wall to aid in removal of theconduit stub-up form; and

FIGS. 13-16 illustrate an adjustable coupling embodiment of a stub-upapplication.

DETAILED DESCRIPTION

The potential problems and hazards associated with conduit or racewaystub-ups protruding above a concrete slab, or other surface, may be atleast partially, and/or completely alleviated by eliminating and/orreducing the conduit stub-up. In some embodiments, eliminating and/orreducing the conduit stub-up may be accomplished while allowing twosections of conduit (e.g., a section of conduit disposed at leastpartially below the finish elevation of the concrete slab and a sectionof conduit to extend upwardly out from the concrete slab) to be joinedor coupled together at least partially within the body of the concreteslab. In some embodiments, the coupling of the two conduit/racewaysections may be accomplished after the placement of the concrete and, insome situations, the two conduit sections may be coupled no sooner thana time when the vertical raceway element can be completely obstructed bypartitions. In an embodiment, the present disclosure may allow a chase,or opening to be created into the surface of the concrete slab andextending down to an embedded coupling within the body of the slab. Asection of conduit may be inserted into the chase, down to the coupling,and coupled to the embedded conduit via the coupling, at a point in timewhen partitions are being installed in the sequence of construction,thus eliminating any potential damage to the embedded conduit and removeany trip or impalement safety issues extending above top of slabelevation.

As shown in the accompanying drawings, a push-on connector or threadedconnector may be attached to a section of conduit that will be below thefinal grade of a concrete slab. Attaching the connector to the sectionof conduit may include attaching the connector to a run of conduit thathas a 90 degree bend in it (e.g., so that the end of the 90 degree bendmay be pointing generally vertically upward), or may include providingthe connector on a short piece of conduit that has a 90 degree bend init, which can be attached to a horizontal run of conduit that will beburied, or embedded, in the slab once the slab is poured. According toeither such situation, or other similarly suitable configurations, agenerally vertically oriented connector may be provided (although inother embodiments, the connector could be horizontally oriented ororiented at an angle, if that is the desired direction of the run ofconduit that will be added after the slab is poured).

In general, a stub-up form may include a sleeve, tube, or other bodythat may be coupled to the connector and may extend upwardly from theconnector to a height that may be above the intended final grade orelevation of the concrete slab that is to be poured. In an embodiment,the stub-up form may be about 6 inches tall, to accept any generallystandard variations in concrete slab thickness. However, the height ofthe stub-up form may vary depending, for example, on an intendedthickness of the concrete slab and a general depth of the connectorwithin the intended concrete slab. As generally mentioned, the stub-upform may be of sufficient height to extend above the surface of theconcrete slab once poured.

The connector may include a metal body or sleeve, that may provide anelectrical connection between the section of conduit buried in theconcrete slab and the section of conduit inserted through the opening inthe concrete slab created by the stub-up form. This electricalconnection may provide a continuous ground between the new piece ofconduit and the conduit buried in the slab.

Example embodiments of a conduit stub-up arrangement may include one ormore of the features set forth below. A push-on/push-in conduitconnector (herein commonly referred to as “push-on” conduit connector)may be attached to a piece of conduit to be embedded/buried in aconcrete slab. A bottom end of the stub-up form/sleeve/tube may bepushed into the other end of the push-on connector so the stub-up formextends above the intended top of the slab to be poured. The stub-upform has sufficient mechanical strength to resist the rigors of concreteplacement and finishing operations—e.g., without breaking or becomingdisplaced. The form may include a gasket or O-ring to seal against theconnector to further protect against concrete or water/moisture seepinginto the connector or raceway. The stub-up form may have a smoothsurface (e.g., plastic such as HDPE) to prevent concrete from bonding tothe stub-up form. The stub-up form may be slightly tapered to make iteasier to pull out of the slab after the concrete sets. The top of thestub-up form may include a hexagonal, square, etc. shape at a point thatwill be above the slab. This allows a wrench, etc., to be used to twistthe stub-up form to screw it out of the push-on conduit connector.

Once the stub-up form is attached to the piece of conduit raceway thatis to be buried in the slab, it may be attached to a separate supportingdevice that is attached to formwork, metal deck or embedded in subgradeto support the entire system during the placement of concrete untilconcrete is cured and sleeve (by itself) is removed from the curedconcrete to leave behind a chase or raceway for the final conduitextension to be inserted through into the connector.

After the concrete slab is poured (with the top of the stub-up connectorsticking above the top surface) and hardens, the stub-up form can beremoved from the concrete slab (e.g., by twisting the stub-up form outof the connector to leave a hole going down into the concrete slab andthe conduit connector buried in the slab. The hole could be about thesame diameter as the outside diameter of a piece of conduit or larger. Apiece of conduit can be inserted through the hole in the concrete slaband secured to the connector to create a continuous conduit runextending from the buried piece of conduit and the buried conduitconnector.

After the stub-up form is removed and before it is time to install thepiece of conduit sticking up out of the slab, a plug could be putin/over the hole to keep debris out of the hole. This cap could be apart of the overall stub-up form that could be detached by only beingperforated to the top of the form and detached at the same time asremoving the form and then inserted into the top of the concrete hole.

Without anything sticking up from the slab (before the next piece ofconduit is attached) tripping, falling and/or impalement hazards mightbe reduced eliminated, while still allowing further pieces of conduit tobe attached to provide continuous conduit runs that go into the slab.

In general, implementations of the present disclosure provide conduitstub-up arrangements that allow in-slab conduit raceway sections to becoupled with conduit raceway sections extending above the slab. In someimplementations, the conduit stub-up arrangements may reduce, oreliminate, any features extending above the surface of the concrete slabprior to the point in time at which the above-slab conduit sections arecoupled with the in-slab conduit sections. By reducing, or eliminating,features extending above the top surface of the concrete slab, thepotential for damage to the conduit raceway (also referred to herein as“conduit”), which could make it difficult and/or expensive to join thedamaged conduit raceway to additional conduit raceway section, may alsobe reduced and/or eliminated. As such, in some embodiments, thepotential time and/or expense associated with repairing damaged conduitstub-ups may be reduced and/or eliminated. Similarly, by reducing, oreliminating, features extending above the top surface of the concreteslab, the potential tripping, impalement, or other safety hazards mayalso be reduced and/or eliminated.

The conduit stub-up form is used with an associated conduit connector inconnection with electrical conduit on a building deck duringconstruction and prior to pouring of concrete. The deck may includeseveral conduit raceways each turned upwardly to a conduit connector.Prior to pouring the conduit, a stub-up form is removably secured to theconnector. After the concrete is poured and hardens, then the stub-upform is removed leaving an opening through which a conduit can beinserted at the appropriate time during the building electricalconstruction phase.

FIG. 1 illustrates a conduit stub-up form assembly 20 in accordance withone embodiment. This is shown in exploded fashion for connection to ahorizontal conduit run 22 having a straight on connector 24 with athreaded end 26. The conduit stub-up form assembly comprises a lowprofile or short radius 90 degree elbow 28 and a removable stub-up form30.

The 90 degree elbow 28 is produced out of a conductive metal such aszinc or aluminum with a standard sweeping radius for approx. 45 degreeswith the remaining 45 degrees being crimped at a single joint tocomplete the 90 degree bend. This type of bend allows for largerdiameter conduit to maintain the coupled joint within the shallow depthsof the concrete slab. The elbow 28 has a first threaded opening 28A atone end and a second threaded opening end 28B at an opposite end. Around flange 32 surrounds the second opening 28B, on the end closest tothe top of concrete, with slots 34 to receive a support standee 36anchored to a form work/substrate 38. The first threaded opening 28A isthreadably connected to the connector 24.

The stub-up form 30, see also FIG. 3B, comprises a hollow plasticcylindrical body 40 formed by an elongate tubular wall 42 having ashoulder 44 connected to a narrowed cylindrical threaded neck 46 closedat a distal end by an end wall 48. The size of the threaded neck 46 isadapted to be received in the second threaded opening 28B of the elbow28. This could be sized for ¾″ conduit or any other size conduit, asnecessary. A cross piece, defined by a central interior wall 50, extendsacross the hollow cylindrical body 40 to aid in removal of the form 30,as described below.

The stub-up form 30 may be formed of one piece plastic construction sothat it is light weight, inexpensive to produce and disposable. Thetubular wall may include a draft of about 1″ and a generally uniformwall thickness of about 0.075 inches. As will be apparent, the inventionis not specifically limited to such a draft or wall thickness.

In use, the stub-up form 30 is removably secured to the elbow 28 bythreading the neck 46 into the second threaded opening 28B. Subsequentto assembly of all the parts, the concrete slab S is poured asillustrated at C in FIG. 1. Once the concrete slab S hardens, then thestub-up form 30 above the slab S can be cut off as illustrated in FIG. 2to expose a remaining part of the stub-up form 30 which is illustratedin cross-section in FIG. 3A. The cutoff stub-up form 30 can remain toprevent debris from falling into the raceway. Prior to installing aconduit, the stub-up form 30 can be removed from the concrete slab usingpliers P or the like to aid in turning the form, as illustrated in FIG.5, to unthread the form 30 from the second threaded opening 28B.Thereafter, a conduit 52 with a threaded connector 54 is inserted intothe hole in the concrete and into the elbow second opening 28B, as shownin FIG. 6. As will be apparent, the diameter of the stub-up form 30,above the shoulder, is slightly larger than the size of the conduit endconnector 54 to allow insertion of the same.

The threaded design of the stub-up form 30 allows for the use of bothEMT (thin-wall non-threaded conduit) as well as RMC (heavy-wall threadedconduit). EMT itself is not threaded, but can be used with threadedfittings or adapters

The threaded stub-up form 30 can be coupled onto the end of a standardbent radius EMT conduit raceway that is embedded in concrete using astandard compression coupling with a threaded female end to receive theplastic sleeve insert that will allow for future access of the conduitraceway. FIG. 4 illustrates use of the same stub-up form 30 with such aconduit raceway 56 having a bend and ending in a threaded connector 58.As such, a stub-up form assembly comprises the form 30 and the connector58. In all other respects, the stub-up form 30 operates similar to thatdiscussed above relative to FIG. 1. In slab-on-grade applications whereRMC conduit is used the threaded connection could be used to eliminatethe separate fitting.

The stub-up form 30 may be manufactured of different sizes according tothe size of the conduit used in the raceway. Moreover, the tubular wall40 may be of a diameter greater than the threaded neck 46 which is of asize to be removably received in the connector second opening 28B. Thetubular wall 40 being of a larger size provides a larger opening thanthe conduit size to provide space for the conduit and any connectors tobe received in the resulting opening and also prevents concrete fromgetting into the connector opening 28B. The outer diameter of thetubular wall may be in the range of ¾″ to ⅞″ greater than the diameterof the neck 46. The invention is not intended to be limited to anyparticular size relationship.

FIGS. 7-11, 12A and 12B illustrate an alternative embodiment. In thisembodiment, a conduit stub-up form assembly 60 includes a conduitstub-up form 62 and a push-on second connector 64B. The push on secondconnector 64B is provided on an elbow 64 with an opposite firstconnector 64A.

Referring to FIG. 12A, the conduit stub-up form 62 comprises a hollowcylindrical body 66 formed by a tubular wall 68 having a shoulder 70connecting to a neck 72 closed a distal end by an end wall 74. Anenlarged head 76 is provided opposite the neck 72 and is configured inthe form of a hexagonal nut, as shown in FIG. 7. The form 62 is ofplastic construction having a generally smooth outer surface. Thetubular wall portion 68 may have a diameter in a range of ½″ to ⅞″greater than a diameter of the neck 72. The tubular wall 68 may have adraft of about 1 and a generally uniform wall thickness of about 0.075inches.

As shown in FIG. 12B, the conduit stub-up form 62 may include a crosspiece defined by a central interior wall 78, as with the embodiment ofFIG. 3B, in the hollow cylindrical body 66 to aid in removal of the form62, as above.

In this embodiment, the second connector 64B may comprise a push-onconnector such as manufactured by Bridgeport Fittings which includes athreading element in the form of a grab ring 80, see FIG. 9, forremovably receiving the stub-up form 62 and subsequently the conduit 52.The grab ring 80 has teeth extending inwardly and turned slightlydownward. The teeth form a helix or spiral. Consequently, the stub-upform 62 can be inserted into the connector by pushing the stub-up formstraight in.

After the concrete is poured, see FIG. 8, then the stub-up form 62 isremoved by turning the stub-up form 62, see FIG. 9. The helical grabring 80 in essence “unthreads” the stub-up form 62, without the use ofactual threads molded in the neck 72. However, the teeth may dig intothe neck 72 to form threads, as shown in FIG. 9.

After removal of the stub-up form 62, then a plug 82 may be temporarilyinserted into the opening in the concrete to keep debris out, as shownin FIG. 10. Thereafter, a conduit 52 may be inserted by pushing it intothe connector 64B to be held by the grab ring 80, as shown in FIG. 11.

With each of the embodiments described herein, a one piece, plasticstub-up form is used which can be temporarily secured to a conduitconnector prior to pouring a deck. After the deck is poured and theconcrete is hardened, then the stub-up form can be removed byunthreading the same, as discussed, to be subsequently replaced by aconduit including a threaded connector or using a grab ring connector,as described.

Moreover, these embodiments disclose a method of providing an in-slabconduit stub-up connection which comprises coupling a first end of aconduit connector to an in-slab conduit. A tubular form is coupled witha second end of the conduit connector, the second end having a threadingelement. The tubular form extends above an intended slab grade. Aconcrete slab is poured surrounding at least a portion of the in-slabconduit and the conduit connector, with the tubular form extending abovethe slab. The tubular form is then threadably removed from the conduitconnector.

In accordance with the methodology described herein, when used with apush-on connector, the stub-up form could include any sort of tube, pipeor standard tube shape, inclusive of conduit directly, which isthreadably removed from the push-on connector after the slab is poured.

FIGS. 13-16 illustrate an adjustable coupling embodiment. In thisembodiment all parts are metallic in composition to maintain continuity.This system allows the raceway to be set flush with the top of concreteelevation with little to no comeback until such time that the walls arelaid out and ready for the vertical continuation of the metallic raceway(either EMT or RMC).

FIG. 13 is an exploded view of the entire system. Starting from the topdown the first part would be described as a flanged closure plug with aflexible spring pendent that can be hit or knocked down and return to anupright position. This will allow the entire assembly to be located evenif the closure plug gets covered with concrete crème or slurry duringthe finishing process. The intent would be that this part would protectthe threaded coupling and able to be removed in the future in order toallow access for the future extension of the vertical metallic raceway(either EMT or RMC). It would also be standard that this part as well asthe coupling that it is threaded into would always be set to be flushwith the final top of concrete elevation.

The next piece is similar to a standard threaded coupling modified tohave a set screw fitting at the bottom to allow this part to betightened down to the male threads of the adjustment shaft that it isthreaded into below it. These two parts work in unison with one anotherand vary in height by approximately ½″ to allow the threaded femalecoupling to be fully tightened down with enough room for the closureplug to be seated flush with the top of the female threaded coupling orfurther extension of the raceway. This part can then be adjusted inelevation approximately the full height of the male threads for which itis adjoined. For example this male threaded adjustment shaft would beapproximately 1½″ and the female threaded coupling would beapproximately 2″ in height leaving approximately ½″ for the closure plugto be seated or threaded conduit to be inserted. This configurationwould allow approximately 1½″ of adjustment for the female threadedcoupling to be leveled with the top of concrete elevation in order tomaintain a perfectly flush trip free connection.

The next part, see FIG. 14, is similar to a compression connectorfitting except that the top end of the male thread is extended to allowfor maximum adjustment that the female threaded coupling can maneuveralong. By eliminating the clamping ring (118), waterproof gasket (114 &142) and the tightening nut (120 & 140) the lower threads (112) can alsobe screwed into the short radius elbow as depicted in FIG. 2 of 3.

FIG. 15 shows the system being used with a short radius elbow and hasthe following original components from the previous definitions orexplanations. The short radius elbow allows for the use of either EMTconduit with the use of transitional fittings as well as RMC (RigidMetallic Conduit). This elbow has a flanged end with oblong knock outsto allow the standee support piece to slip through for support and a tieoff point. The standee has incremental marks measured for elevation fromtop of the deck as well as being crimped to allow them to be bent andbroke off at specific intervals. There are legs on the standee to allowfor concrete to get underneath them in order for them not to be visibleon the underside of the deck once it has been stripped. The screw holesallow it to be tightened down to the supporting deck.

FIG. 16 shows the system being used on an EMT conduit with a standard ortight radius 90 degree bend. This combination is being tied to thesupport standee using standard tie wire between the tightening nuts ofthe compression fitting.

As noted, the stub-up form may be adapted for different sizes ofconduit, as necessary or desired. Likewise, the fittings and elbows andthe like, would be appropriately sized for the conduit being used.

It will be appreciated by those skilled in the art that there are manypossible modifications to be made to the specific forms of the featuresand components of the disclosed embodiments while keeping within thespirit of the concepts disclosed herein. Accordingly, no limitations tothe specific forms of the embodiments disclosed herein should be readinto the claims unless expressly recited in the claims. Although a fewembodiments have been described in detail above, other modifications arepossible. Other embodiments may be within the scope of the followingclaims.

1. A conduit stub-up assembly comprising: a conduit connector comprisinga connector body including first and second openings for selectivelyreceiving conduit end portions, the second opening having a threadingelement and being of a select diameter corresponding to size of conduitend portions; and a conduit stub-up form comprising an elongate tubularwall having a shoulder connected to a narrowed cylindrical neck closedat a distal end, the elongate tubular wall being of a diameter greaterthan the select diameter and the neck having a size to be removablyreceived in the second opening and being engagable by the treadedelement.
 2. The conduit stub-up assembly of claim 1, wherein thenarrowed neck comprises a threaded neck.
 3. The conduit stub-up assemblyof claim 1, wherein the conduit stub-up form is of plastic constructionand wherein the neck can be inserted linearly into the second openingand removed by rotating the conduit stub-up form.
 4. The conduit stub-upassembly of claim 1, wherein tubular wall includes an enlarged grippinghead opposite the neck.
 5. The conduit stub-up assembly of claim 1,wherein the conduit stub-up form is of one piece plastic constructionhaving a generally smooth outer surface.
 6. The conduit stub-up assemblyof claim 1, wherein the conduit stub-up form is hollow.
 7. The conduitstub-up assembly of claim 1, wherein the neck is threaded and thetubular wall portion has a diameter in a range of ¾″ to ⅞″ greater thana diameter of the neck.
 8. The conduit stub-up assembly of claim 1,wherein the neck has a smooth outer surface and the tubular wall portionhas a diameter in a range of ½″ to ⅞″ greater than a diameter of theneck.
 9. The conduit stub-up assembly of claim 1, wherein the tubularwall has a draft of about 1″.
 10. The conduit stub-up assembly of claim1, wherein the conduit stub-up form has a generally uniform wallthickness of about 0.075″.
 11. A conduit stub-up assembly comprising: aconduit connector comprising a connector body including an opening forselectively receiving conduit end portions, the opening having athreading element and being of a select diameter corresponding to sizeof conduit end portions; and a conduit stub-up form comprising anelongate tubular wall having a shoulder connected to a narrowedcylindrical neck closed at a distal end, the elongate tubular wall beingof a diameter greater than the select diameter and the neck having asize to be removably received in the opening and being engagable by thetreaded element.
 12. The conduit stub-up assembly of claim 11, whereinthe narrowed neck comprises a threaded neck.
 13. The conduit stub-upassembly of claim 11, wherein the conduit stub-up form is of plasticconstruction and wherein the neck can be inserted linearly into theopening and removed by rotating the conduit stub-up form.
 14. Theconduit stub-up assembly of claim 11, wherein tubular wall includes anenlarged gripping head opposite the neck.
 15. The conduit stub-upassembly of claim 11, wherein the conduit stub-up form is of one pieceplastic construction having a generally smooth outer surface.
 16. Theconduit stub-up assembly of claim 11, wherein the conduit stub-up formis hollow.
 17. The conduit stub-up assembly of claim 11, wherein theneck is threaded and the tubular wall portion has a diameter in a rangeof ¾″ to ⅞″ greater than a diameter of the neck.
 18. The conduit stub-upassembly of claim 11, wherein the neck has a smooth outer surface andthe tubular wall portion has a diameter in a range of ½″ to ⅞″ greaterthan a diameter of the neck.
 19. The conduit stub-up assembly of claim11, wherein the tubular wall has a draft of about 1″.
 20. The conduitstub-up assembly of claim 11, wherein the conduit stub-up form has agenerally uniform wall thickness of about 0.075″.